TEST SYSTEM FOR A LiDAR SENSOR AND METHOD FOR TESTING A LiDAR SENSOR

Abstract

A test system for a LiDAR sensor, which comprises a trigger detector and a signal generator connected to the trigger detector, the signal generating unit including a display panel having a predefined number of pixels, and the signal generator being configured to aggregate pixels of the same intensity into a cluster. A method for testing a LiDAR sensor is also provided.

Claims

1. A test system for a LiDAR sensor, the test system comprising: a trigger detector; and a signal generator connected to the trigger detector, wherein the signal generator is controlled by the trigger detector in response to the receipt of a trigger signal of a LiDAR sensor to be tested, such that a predefined, artificially generated optical signal or an artificially generated reflection of the trigger signal is output by a signal generating unit of the signal generator, the signal generating unit including a display panel having a predefined number of pixels, and the signal generator being configured to aggregate pixels of the same intensity into a cluster.

2. The test system according to claim 1, wherein the signal generator includes at least two circuit boards, on each of which a plurality of digital/analog converters is arranged, each of the plurality of digital/analog converters being connected to an input of a plurality of crosspoint switches.

3. The test system according to claim 2, wherein particular outputs of the plurality of crosspoint switches are connected to a luminous element driver controlling a luminous element of the signal generating unit or a light-emitting diode or a laser diode.

4. The test system according to claim 3, wherein particular luminous elements of the signal generating unit of each of the plurality of circuit boards are connected to pixels of the display panel assigned to one of the particular luminous element via optical waveguides.

5. The test system according to claim 3, wherein the number of luminous elements of each circuit board is greater than the number of digital/analog converters, wherein the crosspoint switches arranged between the digital/analog converters and the luminous element drivers of the luminous elements are designed to provide a dynamically settable, coordinate connection between the digital/analog converters and the luminous elements.

6. The test system according to claim 2, wherein the plurality of digital/analog converters arranged on a particular circuit board may be controlled by an integrated circuit or an FPGA arranged on the particular circuit board or outside the particular circuit board.

7. The test system according to claim 6, wherein the integrated circuit or the FPGA is connected to an input of each of the plurality of digital/analog converters.

8. The test system according to claim 2, wherein the aggregated cluster of pixels of the same intensity is independent of a shape and/or a time delay of objects represented on the display panel within a measurement cycle of the LiDAR sensor to be tested, and wherein the pixels aggregated into the cluster are assigned to luminous elements of a plurality of circuit boards.

9. The test system according to claim 2, wherein each input of a crosspoint switch is switchable to a plurality of outputs of the crosspoint switch, and wherein each digital/analog converter is configured to control each luminous element.

10. The test system according to claim 1, wherein each cluster generated on the display panel of the signal generating unit is adapted in terms of its size and positioning on the display panel of the signal generating unit from measurement cycle to measurement cycle of the LiDAR sensor to be tested.

11. The test system according to claim 1, wherein an object represented on the display panel of the signal generating unit is divided into a plurality of clusters and the display panel of the signal generating unit includes a curved surface having a predefined radius.

12. The test system according to claim 1, wherein overlapping objects represented on the display panel of the signal generating unit in a measurement cycle, having different intensities and being situated one behind the other are aggregated into a cluster, and wherein distances between the objects are able to be represented by switching off the pixels for a predefined period of time.

13. The test system according to claim 1, wherein a pixel resolution and/or a number of representable intensity graduations of the display panel of the signal generating unit correspond(s) to at least one pixel resolution and/or a number of detectable intensity graduations of the LiDAR sensor.

14. A method for testing a LiDAR sensor, the method comprising: providing a trigger detector and a signal generator connected to the trigger detector; providing a display panel of a signal generating unit of the signal generator, which has a predefined number of pixels; controlling the signal generator by the trigger detector in response to a receipt of a signal of a LiDAR sensor to be tested such that a predefined, artificially generated optical signal or an artificially generated reflection of a LiDAR sensor signal, is output by the signal generating unit of the signal generator; and aggregating pixels of the same intensity into a cluster using the signal generator.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0050] FIG. 1 shows a schematic representation of a test system for a LiDAR sensor according to an example of the invention;

[0051] FIG. 2 shows a schematic representation of a section of the test system for a LiDAR sensor according to the example;

[0052] FIG. 3 shows a schematic representation of a display panel of a signal generating unit according to the example; and

[0053] FIG. 4 shows a flowchart of a method for testing the LiDAR sensor according to the example.

DETAILED DESCRIPTION

[0054] The test system illustrated in FIG. 1 comprises a trigger detector 12 and a signal generator 14 connected to trigger detector 12, signal generator 14 being controlled by trigger detector 12 in response to the receipt of a trigger signal TS of a LiDAR sensor 10 to be tested, in such a way that a predefined, artificially generated optical signal RTS, in particular an artificially generated reflection of trigger signal TS, is output by a signal generating unit 16 of signal generator 14.

[0055] LiDAR Sensor 12 is designed as a flash LiDAR. Alternatively, LiDAR sensor 12 may be formed, for example, by mechanically scanning LiDAR.

[0056] Signal generating unit 16 includes a display panel 16a having a predefined number of pixels 16b. Signal generator 14 is furthermore configured to aggregate pixels 16b of the same intensity I into a cluster 18. The artificial scene is fed into signal generator 14 by a computing apparatus, e.g., a PC.

[0057] Signal generator 14 includes a plurality of circuit boards 20a, 20b, 20c, on each of which a plurality of digital/analog converters 22a-22n, 24a-n, 26a-n is arranged. Each of the plurality of digital/analog converters 22a-22n, 24a-n, 26a-n is connected to an input of a plurality of crosspoint switches 28a-n, 30a-n, 32a-n.

[0058] Particular outputs of the plurality of crosspoint switches 28a-n, 30a-n, 32a-n are connected to a luminous element driver 34a-z, 35a, 39a, which controls a luminous element 36a-z, 37a, 41a of signal generating unit 16, in particular a light-emitting diode or a laser diode.

[0059] Particular luminous elements 36a-z, 37a, 41a of signal generating unit 16 of each of the plurality of circuit boards 20a, 20b, 20c are connected to a pixel 16b of display panel 16a assigned to particular luminous element 36a-z, 37a, 41a via optical waveguides 38a, 38b, 38c, 38d.

[0060] FIG. 2 shows a schematic representation of a section of the test system for a LiDAR sensor according to the preferred specific embodiment of the invention.

[0061] The number of luminous elements 36a-z of circuit board 20a is greater than the number of digital/analog converters 22a-22n. Crosspoint switches 28a-n arranged between digital/analog converters 22a-22n and luminous element drivers 34a-z of luminous elements 36a-z are furthermore designed to provide a dynamically settable coordinate connection between digital/analog converters 22a-22n and luminous elements 36a-z.

[0062] The plurality of digital/analog converters 22a-22n arranged on circuit board 20a is controllable by an integrated circuit 40a, in particular a field-programmable gate array (FPGA), arranged outside circuit board 20a.

[0063] Alternatively, the plurality of digital/analog converters 22a-22n arranged on circuit board 20a may be controllable by an integrated circuit 40a, in particular an FPGA, arranged, for example, one circuit board 20a.

[0064] Each input of a crosspoint switch 28a-n is switchable to a plurality of outputs of crosspoint switches 28a-n.

[0065] Each digital/analog converter 22a-22n is configured to control each luminous element 36a-z.

[0066] The control of which pixels are to be active at which point in time and in which intensity is implemented in the integrated circuit, in particular the FPGA. The corresponding digital signal of the surroundings simulation generated by the computing apparatus is first converted into an analog signal and then used as the input signal for luminous element driver 34a-z.

[0067] The invention is based on the finding that it is not at all necessary to use as many different intensity values as existing sensor pixels. The goal of pixel panel or display panel 16a is to emulate a point cloud, which LiDAR sensor 10 sees in real use.

[0068] Viewing a point cloud as the simulation result to be achieved leads to the finding that only a limited number of different intensity values need to be depicted.

[0069] A cluster 18 or pixel aggregation cluster is defined by luminous elements 36a-z belonging to an intensity cluster.

[0070] Viewed globally, multiple digital/analog converters 22a-22n per cluster 18 may thus also supply the same intensity value. This then implies that the entire display panel may theoretically be one large cluster 18.

[0071] However, a cluster 18 does not have to have anything to do with the shape of an object. The associated luminous elements may be situated anywhere, they need only to have the same intensity value at the same point in time during the feeding of the scene.

[0072] Signal generating unit 16 is designed in such a way that the intensity value of the aggregated pixels may vary from distance to distance. Pixel enable signals are provided for a sub-selection of the pixels at a distance. Clusters 18 are redefined from scene to scene or from frame to frame of the surroundings simulation.

[0073] There are only as many intensities as digital/analog converter channels at one point in time, i.e., at a distance from the sensor; however, they may then be selected arbitrarily. Even if only a few intensities are available overall, they are generally sufficient.

[0074] It is advantageous that certain regions may have a higher resolution, i.e., more intensities per pixel surface area, while other regions have a lower resolution. This assignment may be dynamically varied from scene to scene.

[0075] FIG. 3 shows a schematic representation of a display panel of a signal generating unit according to the preferred specific embodiment of the invention.

[0076] Aggregated cluster 18 of pixels 16b of the same intensity I is independent of a shape and/or a time delay of objects 42a, 42b, 42c represented on display panel 16a within a measurement cycle of LiDAR sensor 10 to be tested.

[0077] Moreover, pixels 16b aggregated into cluster 18 may be assigned to luminous elements 36a-z, 37a, 41a of a plurality of circuit boards 20a, 20b, 20c. Each cluster 18 generated on display panel 16a of signal generating unit 16 may be adapted in terms of its size and positioning on display panel 16a of signal generating unit 16 from measurement cycle to measurement cycle of LiDAR sensor 10 to be tested.

[0078] An object 42a, 42b, 42c represented on display panel 16a of signal generating unit 16 may be divided into a plurality of clusters 18.

[0079] Display panel 16a of signal generating unit 16 preferably has a planar surface. Alternatively, display panel 16a of signal generating unit 16 may have a curved surface with a predefined radius.

[0080] Overlapping objects 42a, 42b, 42c, which are represented on display panel 16a of signal generating unit 16 in a measurement cycle, have different intensities I and are situated one behind the other, may be aggregated into a cluster 18. Distances between objects 42a, 42b, 42c may be represented by switching off pixels 16b for a predefined period of time.

[0081] A pixel resolution and/or a number of representable intensity graduations of display panel 16a of signal generating unit 16 correspond(s) to at least one pixel resolution and/or a number of detectable intensity graduations of LiDAR sensor 10.

[0082] Different intensities may be generated either from distance to distance or from cluster 18 to cluster 18. A pixel region of display panel 16a controllable by a circuit board may be identified as a black frame. The functionality may be recognized based on the example of the pedestrian in the front right region of the image as the target and an overlapping of the target over multiple circuit boards.

[0083] The head has a medium-high intensity, the body a high intensity, the legs a medium intensity and the hand a low intensity. The intensity is associated with the reflectivity of the target surface and the distance from the sensor.

[0084] The truck may also be effectively represented, depending on its position in the image region, in that the upper glassed-in cab may be delimited from the rest of the truck, which has a metallically high reflectivity.

[0085] The lower part of the truck is a cluster 18 of uniform intensity and extends over two circuit boards.

[0086] The depiction of the simulated distance of an object is shown by the time delay of the signal emitted by the pixels. Objects having different distances, which are then represented by pixel panel 16a at different points in time, may thus occur in one scene.

[0087] The intensity values may still be varied between the different distances, or pixels may be switched off by enable signals. Due to the long switching times of crosspoint switches 28a-n, 30a-n, 32a-n, a variation of clusters 18 may take place only after each measurement cycle of sensor 10. Within the scope of these restrictions, even objects situated one behind the other at different distance from sensor 10 may be represented by the same pixels 16b.

[0088] FIG. 4 shows a flowchart of a method for testing the LiDAR sensor according to the preferred specific embodiment of the invention.

[0089] The method comprises a provision S1 of a trigger detector 12 and a signal generator 14 connected to trigger detector 12.

[0090] In addition, the method comprises a provision S2 of a display panel 16a of a signal generating unit 16 of signal generator 14, which has a predefined number of pixels 16b.

[0091] The method also comprises a control S3 of signal generator 14 by trigger detector 12 in response to the receipt of a signal of a LiDAR sensor 10 to be tested, in such a way that a predefined optical signal generated by a computing apparatus, in particular, an artificially generated reflection of a LiDAR sensor signal, is output by signal generating unit 16 of signal generator 14.

[0092] The method further comprises an aggregation S4 of pixels 16b of the same intensity I into a cluster 18, using signal generator 14.

[0093] Although specific embodiments have been illustrated and described herein, it is understandable to those skilled in the art that a multiplicity of alternative and/or equivalent implementations exist. It should be noted that the exemplary embodiment or exemplary embodiments is/are only examples and are not used to limit the scope, the applicability or the configuration in any way.

[0094] Rather, the aforementioned summary and detailed description provide those skilled in the art with a convenient set of instructions on the implementation of at least one exemplary embodiment, it being understandable that different modifications in the range of functions and the arrangement of the elements may be carried out without deviating from the scope of the attached claims and their legal equivalents.

[0095] This application generally intends to cover changes and adaptations or variations in the embodiments illustrated herein.

[0096] The LiDAR sensor may be formed, for example, by a mechanically rotating, scanning LiDAR. In this case, display panel 16a of signal generating unit 16 would be arranged at an angle of 360° around LiDAR sensor 10.

[0097] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.